Animal Instincts
by celestial-fire-angel
Summary: SxYY MPREG! Yami is introduced into the world of Zoomanity as a rare missing link. Seto just wants Yami for his body. Can these two survive the crazy Zoomanity world together?
1. Chapter 1

**Title:** Animal Instincts

**Author:** celestial-fire-angel

**Rating:** M for language and future adult situations, as well as mpreg.

**Pairings:** S x Y mainly

Disclaimer: I do not own YGO or Love Pistols, just borrowing the characters and concepts, respectively.

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**Author's Note:** Hey guys, welcome to my new story Animal Instincts. I know I shouldn't be starting a new story without finishing my other ones but I have inspiration for this one so this is gonna get written. At least the creative juices are flowing for this one! I hope everyone likes it.

Chapter 1

Yami rubbed his eyes as he looked around him, was he seeing things? Even after rubbing his eyes, he still saw a whole train full of…monkeys? What the hell was going on here? Why did the people look like monkeys…and there were even some dogs and bears. Now he was confused and he tried hard not to stare but he couldn't help it. It wasn't every day that people started to look like animals for no good reason. He checked the date on his watch just to make sure it wasn't Halloween, which it wasn't. Cherry blossoms didn't bloom in the fall so that meant he wasn't seeing things. There really were monkeys with him, riding the train.

His visions of seeing animals instead of the real person started when he came back home after an accident involving a pool, a flip turn, and a concussion during his seventeenth birthday party, held by his closest friends. When he came to, in a hospital, he saw the doctor as a bear and nearly gave the doctor a concussion after throwing everything he could at him, missing with the bedpan by only a few centimeters. Even his brother, who was by his side, looked like a feline dressed in their school's uniform.

He snapped out of his daze when he felt hands touching him. Oh great, now he was with a train full of perverted monkeys who were trying to feel him up, what a great day this was turning out to be. His free hand, the one not holding onto the handhold, balled into a fist. He was close to punching all the perverts' lights out if they didn't back off in three…two…on-

BAM!

The train jerked and all who had been touching him were thrown to one side. Just in time too, the conductor announced his stop. He was eager to get away from those horny monkey bastards who couldn't keep their hands to themselves. Stepping off the train into a throng of people at the station, he brushed himself off, hating the lingering feel of some of those who had the nerve to touch him inappropriately.

It wasn't much better at the station. He was still seeing animals though now there was more of a variety, which didn't help. Quickly, he pushed through the sea of people and hurried towards school. He checked his watch again. If he ran the last third of the way, he could make it before the teacher arrived. When it wasn't so crowded on the streets, he sprinted through the gates of his school and dashed up the stairs, throwing open the doors to his classroom, out of breath but safe. "Made it," he muttered.

"Yo, close call, Yami."

"Hey Jou," Yami gasped, falling into his seat next to his best friend, one Jounouchi Katsuya, trying to catch his breath. He was trying hard not to stare at his friend. It didn't help that he currently looked like a dog, but not just any dog, he looked like a really large beagle or some other non threatening-looking dog.

"You looked pissed. Somethin' happen?"

Yami sure as hell wasn't going to tell him how he was felt up by a large mob on the train. "No, everything's fine." Or it will be as soon as he stopped seeing everyone as animals.

"Someone spray perfume or something on you?"

"What?"

"You smell really good…"

What the hell was Jou talking about? He lifted his arm and smelled his sleeve. All he could smell was the detergent he had used to wash his uniform but that was about it. "I don't smell like anything, Jou."

"Yeah you do…can't really describe it, but you do. Really good."

Before Yami could figure out what was going on, Jou was leaning towards him, glazed look in his eyes. "Uh…J-Jou?" Yami leaned back as Jou leaned forward not understanding what was going on. Jou looked like he wanted to…kiss him. "Jou? Jou!" It was only when Yami was practically screaming at his friend did Jou look like he came to his senses.

"Uh…hey Yami," Jou said, blinking. Aware of the whispers, the blond quickly sat up and faced forward, a bit embarrassed he had let his body take over his mind instead of the other way around. "Uh…" He wasn't quite sure what to say next because he had just embarrassed himself in front of all his classmates. He was well aware of the snickering going on behind them.

"Yeah," Yami just said, pulling out his notebook. Never had he been so glad to see the teacher walk into the classroom to start class.

~.~.~.~

"Come on, wake up, you'll be late for the rest of your classes!"

"I'm not going, I just finished with all those meetings yesterday. Besides, why aren't you at school?"

"Kaiba Seto, get your butt out of bed this instant! I'm here because I forgot something here."

With a rough yank, one Kaiba Seto found himself covered only by the pajamas he had thrown on haphazardly the night before when he collapse into bed after a long day of meetings with his board of directors. Sighing, he sat up and glared bleary-eyed at his brother, who stood there with his blanket gripped in both hands. "Mokuba, I'm serious, let me sleep."

"You're not missing any more school."

"Mokuba…" his voice now held a warning tone. He was in no mood to deal with this right now.

"Go to school, Seto, besides, you're looking for a mate right?"

"Who told you that?" In Seto's opinion, Mokuba was too young to be thinking and talking about mates or mating, even if he was intelligent for his age.

"A little pixie flew out of your brain and told me."

"There's no such thing as pixies and it's impossible for them to fly out of people's brains," Seto pointed out dryly, getting out of bed. There was no point in going back to sleep now that his brain was awake. Mokuba managed to get the best of him again. Him, Kaiba Seto, the youngest CEO in Japan, was bested by his little brother, a feat no one in the adult world had managed that.

Mokuba rolled his eyes at Seto's comment. His brother's sense of humor was as dry as the Sahara. "_Anyway_, they say there's a missing link right at our school!"

At this, Seto perked up and paid more attention to what his brother was saying. A missing link would be the perfect mate for him. Missing links were rare, born from apeman(normal human) parents who had a zooman ancestor. Mating with a missing link would definitely continue his lineage. He, a dragon heavyweight had a hard time breeding because of his weight class. Lightweights, at the bottom of the zoomanity pyramid, were the most fertile of the zoomen followed by middleweights and then heavyweights.

Zoomanity was divided into different class systems and ordered from rarest to most common. There were seven types of zoomans: Merfolk, Missing Links, Dragon, Bruin, Catamount, Dog Gods and Snake-Eyes with Merfolk being the rarest and Dog Gods being the most common. The types were further divided into three weight classes: lightweight, middleweight and heavyweight. Due to the high infertility rate that plagued heavyweights like Seto, most of the heavyweights chose to mate with lightweights or middleweights in order to continue their lineage but Seto was not going to stoop that low. He searched for a missing link, which had all the necessary rare qualities he was looking for with the fertility of the apeman.

"Our school, a dump like that, crawling with monkeys and dogs all over the place, can provide a missing link," he said to himself, going to his closet and pulling on his school uniform. He reminded himself that it was to meet the missing link and that the future of his line depended on this meeting.

"The car's already waiting," Mokuba chirped, skipping out the door. He won the battle today.

~.~.~.~

When the bell rang for lunch, Yami was first out the door. He needed to get out of there, needed to find some space for himself. The only place he could think of was on the roof of the school. Taking the stairs three at a time, he pushed through the people who were staring at him, the same glazed look that Jou had gotten that morning.

Pushing open the heavy metal door, he stepped out onto the roof and took a deep breath. He was free, at least for the moment. He walked to the edge of the roof, looking out across the school grounds at his schoolmates spilling out to enjoy lunch in the spring air. Letting his messenger bag settle on the ground, he sat down and leaned against the metal chain-link fence surrounding the roof. Now to have his lunch in private with no worry about anyone coming ont-

"There you are!"

Damn, how did people manage to find him even up here? He was not safe anywhere anymore! Looking up, he saw the slu-er…most popular girl in school sauntering over to him, skirt hiked up a few inches than was regulation but no one cared. He wanted to make a hasty retreat but she had already advanced too close for him to do much.

"Yami," she purred, folding her arms under her chest. Yami tried not to gag at the sight of Himekouji Kaoruko practically spilling out of her blouse.

"Himekouji," he said, giving her a nod in acknowledgement. He stuffed his lunch back into his bag and stood up, edging his way towards the door.

"You can call me Kaoruko," she said, following Yami, matching his steps.

Like hell he was going to be on a first name basis with this…person. He was trying hard not to be impolite but she was pushing, really pushing it, and he wasn't talking just about her chest. He took his eyes off of her for a moment to judge the distance he would have to sprint to reach the door but in that moment, she had closed the distance and tackled him to the floor. "What are you-!"

"You'll enjoy this, Yami," she cooed in her sickeningly sweet voice, unbuttoning her blouse faster than he thought was humanly possible.

"Get off!" No way this was happening!

She now straddled his legs, making it impossible for him to move or try to make an escape. Was this it? Was he about to be…raped by a girl?! Unbelievable! But it seemed that way…she was sitting directly over his groin, grinding against him and pushing her breasts into his face.

"I'm about to give what's most precious to you, dear Yami," she said with a giggle that sent chills down Yami's spine.

Yami opened his mouth to reply that she had already lost that year ago, probably to some guy she didn't even know but nothing came out. When had she unbuttoned _his_ shirt? How was that even possible? She was moving closer, her face inching closer to his. He could smell the cherry of her chapstick…it couldn't be this way…he couldn't lose his virginity this way…oh gods, any moment and he would feel those monstrous lips, greasy from the chapstick and disgustingly wet. Curse his chivalry, curse it, curse it, curse!

"So, this is the missing link."

A new voice interrupted and Yami looked up to see a tall brunet looking down at them. His face turned scarlet, matching the tips of his hair at being caught in this situation by someone. But he was grateful when Kaoruko let out a shriek and got off him, running towards the door while fixing her clothes. With her gone, Yami stood up and brushed off his clothes, knowing he would have to wash this uniform again to get rid of her scent.

"I suppose that means I have to thank you?" he asked the brunet. To his surprise, the brunet looked…normal, meaning he looked like an actual person.

"No, just let me fuck you."

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**Author's Note:**I hope the whole zoomanity pyramid thing was understandable! If not, I'll go into more detail in later chapters, promise!

Read and Review! Thank you!


	2. Chapter 2

**Title:** Animal Instincts

**Author:** celestial-fire-angel

**Rating:** M for language and future adult situations

**Pairings:** S x Y mainly

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Disclaimer: I do not own YGO or Love Pistols, just borrowing the characters and concepts, respectively.

**Author's Note: **Thank you everyone for the encouraging reviews! I hope you like this chapter as well!! For the fans of 'To My Enemy I've Come to Love' fear not! I haven't forgotten it, I'm just having a bit of writer's block for that story so please be a bit more patient with me~ Please continue to support me, thank you!

**Chapter 2**

Had he heard right? Did this guy just say he wanted to screw him? "W-What the hell?!" He couldn't believe what he had just heard. There were people this crude that existed?

"Let me fuck you. You're the missing link, right?" Cobalt blue eyes scanned over the smaller male's body, taking in the slender frame, the disheveled clothes and most of all, the ridiculous amount of gravity-defying hair. Seto wondered how many cans of hairspray it took to reach that level of stiffness. Speaking of stiffness, his body was doing a good job of keeping his mind focused on what he was here for.

"I don't know what you're talking about!" What the hell was a missing link?

"I don't have time to explain," he said, grasping a thin wrist and tugging him towards the door leading to the stairs. He could clearly see that his claim was being threatened and Seto did not take well to threats. He was a dragon heavyweight, just under missing links in terms of power* and he wasn't going to let any inferior zoomen have a go at what was his. "We're leaving."

Yami dragged his feet and tried to yank his wrist from him. "I'm not going anywhere with you. Who the fuck are you?!"

"The guy who's going to fuck you," Seto said nonchalantly. His grip tightened and he looked to the struggling boy. "You're having my baby."

The smaller teen stood still, struck dumb by what he had said. A baby? How the…was he a mentally ill person who escaped from a psychiatric ward? "You psycho, what the hell are you talking about? I'm a guy!" The last time he listened in biology class, girls were the ones to have the babies, not boys and the last time he checked himself, he was very much a boy.

"Doesn't matter, you're having my baby." He was annoyed at having to repeat himself. Was this missing link also missing a few brain cells? Just his luck that the one missing link he finds has to be an idiot. But he could care less about the smaller teen's mental capabilities. He only needed his fertility.

"Are you deaf as well as stupid?" Yami demanded, tugging against the taller male. "I said I'm a GUY! Know what that means? It means I can't have kids, nutcase."

Seto scowled. Who knew that a missing link was this much trouble! Were all missing links like this or was this one just special? To top it all off, his phone was vibrating and that could only mean one thing: getting back to work. "Fuck," he growled, whipping out the phone and answering it, not one bit happy. "What?...What the hell! You incompetent fools, can't you do anything right? Why the fuck did I hire you useless idiots?! Alright, stay there, I'm heading over…" Snapping the phone shut with a louder than necessary click, he huffed an annoyed breath. "The people I have to deal with," he muttered. Well, there was no helping it now, he had to go, but not before doing something about this missing link. He wasn't going to take anyone's sloppy seconds so that meant marking this one as his, just long enough to keep him pure until he came back.

He pulled Yami, roughly, towards the door, ignoring the protests from the smaller male. Now that his time was cut short, he'd have to be quick about it. He wasn't going to chance his company going down in ruins because a few brainless bastards didn't do their jobs. Keeping a firm grip on the struggling male, he pushed him rather roughly into a bathroom stall. "Not a sound," he growled, loosening his belt and pushing his pants down.

Yami's eyes grew wide. "W-what the fuck are you doing?!" A million thoughts rushed through his head all at once and he tried to back away from this psycho who was probably about to rape him or something.

"Quiet!" Seto didn't want to hear any complaints. He was frustrated enough. With long, elegant fingers, he gripped himself, using his own juices to lubricate. The heady scent the missing link was giving off was almost enough to push him over the edge. Almost.

What the hell was going on? Yami tried his hardest not to stare but there was nowhere else to look…except up but when he looked up, he saw the psycho's face. He wasn't sure which was more disturbing to look at. He closed his eyes but the sounds were there and…wait, what was that? He sniffed gingerly and his eyes opened again slowly. Where was that smell coming from? He couldn't accurately describe the smell just it…smelled good, really good. It smelled like a…male.

"Hey, look sexier, this isn't cutting it for me."

The other's voice brought him out of his stupor and he blinked a couple of times. This guy actually was perverted enough to ask that of him, considering their situation. As stubborn as he was and as much as he didn't want to do it, he couldn't help but be affected by that smell. It made his whole body tingle and grow hot. What was happening? It was stronger now and he found himself leaning forward, towards the pervert. He wanted to resist, his brain screaming at him to stop but his body wasn't listening. He trembled and his cheeks were flushed as he looked up at the other with his own lust filled eyes. A small sound came from his throat and he barely registered it. It sounded more like a 'meow' than any other sound he could have made.

"There you go," Seto said. There was that face he wanted to see. The flushed face was just what he needed…he stroked faster, a low rumble coming from his own chest despite himself. Every muscle tensed and his head fell back as a flash of white streaked across his vision. A moan erupted from his chest as he felt his release spurt forth.

Yami blinked a few times when he felt something warm hit his cheek. He came back to his senses and when he realized just what was on his face, he let out a shriek. "WHAT THE FUCK?!!"

Panting and trying to catch his breath, Seto growled softly. "Shut the fuck up." The smaller male's screaming was getting on his nerves and he didn't need a migraine before work. It had to be done to protect what was he had claimed. Reaching across the small space separating him and the missing link, he made sure to rub his scent all over the other, massaging it deep into his skin.

"What the hell? Get off!! Perverted bastard!!" He slapped away the other's hands, not wanting him to touch him, not after what had happened. He was confused and a little scared, which was quite a feat since Yami wasn't scared of most things. He didn't understand why this…this beast had to do something like _that_ to him. He didn't even know him! And what the hell was a missing link? Nothing this guy ever said made any sense to him.

"Didn't I say shut up?" Seto hated repeating himself. It made him feel like he was back at the office talking to his incompetent workers…speaking of which, he checked his watch after he straightened his clothes again. "Shit, I'm late." If this stupid missing link wasn't so damn precious to zoomanity and if he had just cooperated, he wouldn't have been late like this. "I'll pick you up tomorrow. And don't you dare wash it off!" And with that, he unlocked the door to the stall and headed off to work, leaving the other there.

Could this be considered rape? A million questions were whirling inside of him and he didn't have any answers. Taking a few minutes, he collected himself and ran out of the stall and to the sinks. He splashed water on his face and tried to clean himself off. To hell with that bastards words because he was not walking around with some guy's jizz on his face. Shuddering, he wiped his face with a paper towel and walked out. He calmed himself enough to appear normal on the outside but it wasn't the same story on the inside. Though despite everything, he managed to get through the rest of the day without any other incident.

~*~*~*~*

The next day, Yami was cautious, looking around him, trying to see if that pervert was back. He had a name but 'pervert' sounded like a more appropriate name. He had wanted to stay home but his grandfather wasn't going to hear any of that. The same speech about how school was important and that he hadn't raised Yami to be a shut-in echoed through his head. It was the same speech every time and Yami had memorized the speech, saying it along with his grandfather. Of course his grandfather had been oblivious to his voice and had continued to lecture him until Yami interrupted him and told him he was off to school. He ran out of the house, not paying attention to his grandfather shouting at him to wait until the end of the speech. As much as he loved his grandfather, the old man could be overbearing some times. But Yami was grateful. He was appreciative of his grandfather taking in both him and his brother after his parents died. His brother was still at the junior high, getting ready to move up into high school next year. Though from what Yami was going through, he wasn't sure he wanted his brother going here.

After yesterday, Yami would bet that anyone would stay home, anyone other than him that is. But today had a different feel to it, something was very different. He couldn't quite place what it was just yet.

"Hey Yami, how're ya do…ing." It was Jou. It was surprising to see Jou, who was over him yesterday, actually take a step back instead today. And…he was human! Well of course he was human just that he looked like one today.

"Hey Jou…oh you don't look like a dog today," Yami said, finally noticing what was different about today. When he had gotten up, his grandfather has looked normal, not like a monkey at all. The train ride to school had been normal too with no perverts groping him. Actually everyone seemed to take a step back from him just like Jou had done. Everything seemed to be back to normal just like they did before his swimming accident.

"What the…I look like some kinda dog?" Jou asked. He patted the top of his head just to be sure his true soul wasn't showing. A true soul was the spirit of the zoomanity animal assigned to each individual zooman. It was sacred and to have a true soul showing was somewhat taboo, especially if the other person wasn't a loved one and even then, it was only in certain circumstances where the true soul could be shown. Had he inadvertently shown Yami his true soul?

"No, well…yesterday you did," Yami said, thinking about what Jou had looked like. Was it more of a beagle or…no, it looked more like a hybrid.

Jou hadn't shown his true soul yesterday, he made sure, especially after the incident with Yami before class had started. So that had to mean that Yami was aware of zoomanity which meant that Yami was a zooman. He should have known yesterday but was too busy keeping his hormones in check to make sure and after that, Yami had disappeared. They only had a couple of classes together so he didn't see his best friend at all during the afternoon. "Uh right…so you know about zoomanity," he stated. Stated, not asked.

"Zoomanity?" he asked. He had never heard the term before and didn't know where to start. Wait, that bastard had said something about a 'missing link'. At the time he had been too busy trying to get Himekouji Kaoruko off of him to ask what that was. And after that…he was too stupefied by what happened to ask the pervert.

"Kinda complicated ta explain," Jou said, rubbing the back of his head. "Guess you'll have to come over so I can start explainin'. Though…" The smell coming from Yami wasn't the same as yesterday. It smelled like a certain someone who Jou had come to detest…had something happened between Yami and that guy? "Uh Yami, did somethin' happen yesterday? You smell kinda different today."

He smelled different? Sniffing his sleeve, Yami looked back to Jou. "Um, I do?" All he smelled was detergent and his house but that was it. "What do you mean?"

"Uh…ya smell like this guy…"

"Is that bastard's name Kaiba Seto?!" As soon as Jou said he smelled like someone, he instantly knew that it was probably the one who had done _that_ to him.

Oh shit, it _was_ him? "What'd he do to ya, Yami?" There was a hint of a growl in his voice, much like a puppy's.

Yami couldn't believe he didn't notice it before and he tried hard not to laugh despite the topic of discussion. His mind battled itself, wondering if he could tell Jou what had happened yesterday. Jou was his best friend but something like this…Yami just wasn't sure. It was too embarrassing even to tell his best friend. "Nothing," he said a little too quickly.

Jou knew Yami was lying and if Yami was lying then it had to be something bad. Growling louder, he stood up, fists clenched. He was going to kill that bastard for whatever he did to Yami. No one messed with his best friend and got away with it. He didn't need to get far at all. He barely made it to the door when who should walk in but the bastard they had been talking about.

"Where's Mutou?"

Yami just stared as his assailant sauntered into the room, cobalt blue eyes scanning the room and finally ending up where he sat. What in the world could he want?

"Yo pretty boy, step outside, gotta talk to ya," Jou said, stepping between Seto and Yami. He was going to give this bastard a piece of his mind.

Seto was about to take a step towards the missing link when someone dared to get into his way. Oh great, it had to be the missing link's little puppy. Did this dog not know the rules? Even a heavyweight dog god was beneath his heavyweight dragon type and in Seto's opinion, too far below to be able to do something to him. "Stop barking, Mutt," he growled. He only wanted to talk to Mutou and not anyone else. He had something to give him…well courtesy of his brother. Mokuba was good at guessing and knew Seto probably hadn't handled it with as much tact as he did his business and so gave him a booklet to give to Yami. Of course Seto had been adamant about not going back to school but if there was one person able to make him, it was Mokuba.

M-Mutt? Never had he been called…wait, that wasn't true but never had this arrogant asshole…no wait, that wasn't true either. Kaiba had a habit of ragging on him, calling him a mutt ever since they had first seen each other. That wasn't the problem at the moment!! Shaking his head to focus, he didn't move from where he stood. "Got a problem?" he asked, none too friendly.

"Shut the fuck up before I call animal patrol," Seto said, walking past the growling dog god and grasping the other teen's wrist. "Before the dog starts foaming at the mouth, here. Read it." Unceremoniously, he slapped the booklet into Yami's hand and without another word, walked back out of the classroom.

What had that been about? Yami didn't even have time to register what the bastard had given him before said bastard left. Turning the booklet over, he read 'A Beginner's Guide to Zoomanity: From the Basics.' He was already hating the book with its ugly blocky print and hideous vibrant oranges, yellows and pinks and blues meant to appeal to children. What the hell was this and what the hell was Zoomanity?

**Author's Note:** So how was that chapter? Please let me know!! If I don't get at least ten to fifteen reviews, I might just scrap this whole story, please don't make me do that!

Read and Review!! Thank you!


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